Token Configurations

On any single line with more than one token section, it
is essential that the tokens of adjoining sections differ in some form
or the other. They can be of different shapes, colours and where
electric tokens are used, have different configurations of notches etc
to only allow them to be used in the correct machine for the section.

TYER KEY TOKENS

Tyer keys come in a variety of shapes and colours but the feature
that distinguishes the key from its neighbours is the slot on the key
end. The following is a view from the handle end of a token, showing the
relative positions of the slots.

As stated, the slot is what determines the configuration
but as an extra aid to identification keys can have additional features.

In some cases the key handles are of different shapes
and have a central hole, the handle and the hole shapes being 'A' Round,
'B' Square, 'C' Triangular, 'D' Diamond (square turned through 45
degrees).

Some key token handles are all the same shape regardless
of configuration but have the central hole.

Others, the handles are the same shape but they are
painted to indicate which configuration they are, 'A' Red, 'B' Blue, 'C'
Green, 'D' Yellow.

The picture below shows how the configuration is set on
the instrument, this protrusion only allows key tokens of the same
configuration to enter the instrument, in this case it is set at the 'B'
configuration. The protrusion is part of a metal plate that can be fixed
in any one of the four standard configurations.

TYER No 1 TABLETS

On Tyer No 1 tablets the configuration is determined by
the relative position of the slot on the circumference and the small
hole.

Note - Although I have annotated the sketch below with
the configurations A-C, I have found no evidence that this is in fact
correct. (If you know the correct annotation, please let me know!)

Some tablets have a central hole, some just have a
depression in the centre, to aid identification. Being the first design
of electric token, the shape of this central hole/depression doesn't necessarily
follow the accepted standard that latter tokens adopted.

The
photo below shows the raised lid of a No 1 Tablet machine, at the bottom
of the picture you can just make out the nib which engages with the slot
cut in the side of the tablet. On the lid is the pin that engages with the
hole in the tablet. In this case the pin is in the 'B' configuration, and
shows three other possible positions and room for another.

TYER No 6 TABLETS (also No 2, 3, 5 & 7)

On these tablets the configuration is purely the shape
of the notch at the bottom. The hole at the top, unlike the No 1
tablets, does not play a part in the configuration. Most tablets also
have a central cut out which normally follows as below.

The slide where the tablets are inserted into the machine, has a
corresponding nib to match the configuration of the tablet, The picture
below shows an 'A' configuration, as fitted to a Tyer No 6 instrument.

LARGE STAFFS

The configuration is determined by the position of the 5th ring, as an
additional aid the staffs are sometimes painted, however most of this
paint doesn't survive in service.

MINIATURE STAFF 'M' TYPE

These staffs dispensed with the 5th ring and the configuration is
determined by the position of the small collars, to ensure that the
staff is inserted the correct way into the instrument one pair of rings
are a larger width than the other pair.

MINIATURE STAFF 'S' TYPE

The configuration arrangements are identical to the
'M' type above. To ensure the staffs are inserted into the instrument
the correct way, the rings (which are all the same width) are spaced
differently.